[Rcpp-devel] 'Nested' Rcpp functions using inline

[Rubem Kaipper Ceratti]

Jeffrey, thanks a lot!


________________________________
 De: Jeffrey Pollock <jeffpollock9 at gmail.com>
Para: Rubem Kaipper Ceratti <rubem_ceratti at yahoo.com.br> 
Cc: "rcpp-devel at lists.r-forge.r-project.org" <rcpp-devel at lists.r-forge.r-project.org> 
Enviadas: Quarta-feira, 10 de Outubro de 2012 11:59
Assunto: Re: [Rcpp-devel] 'Nested' Rcpp functions using inline
 

I think you need to use the `includes` argument of cxxfunction to include a pure c++ function ie;

library(inline)
library(Rcpp)

inc <-'
        int fun1(double x, double y) {
            return (exp(x) - y) > 0 ? 1 : 0;
        }
        '

body <-'
        NumericVector u   = as<NumericVector>(u_r);
        double        mu  = as<double>(mu_r), 
        v   = log(mu);
        int           n   = u.size(),
        res = 0;
        
        for(int i=0; i<n; i++){
            res += fun1(u(i), v);
        }
        
        return wrap(res);
        '

fun.test <- cxxfunction(signature(u_r = 'numeric', mu_r = 'numeric'), body, "Rcpp", inc)

> identical(fun.test(1:4, 100), sum(exp(1:4) > log(100)))
[1] TRUE


On Wed, Oct 10, 2012 at 3:39 PM, Rubem Kaipper Ceratti <rubem_ceratti at yahoo.com.br> wrote:

Hi,
>
>
>I'm currently using Rcpp and inline to speed up some R code I wrote, but being a C++/Rcpp newbie I'm running into some difficulties. More specifically, I'm having problems calling an Rcpp function inside another one. As a toy example consider the code:
>## 
>library(Rcpp)
>library(inline)
>
>
>code2.0 <-'
>  NumericVector u   = as<NumericVector>(u_r);
>  double        mu  = as<double>(mu_r), 
>                v   = log(mu);
>  int           n   = u.size(),
>                res = 0;
>
>
>  for(int i=0; i<n; i++){
>    res += (exp(u(i))-v) > 0 ? 1 : 0;
>  }
>
>
>  return wrap(res);
>'
>sig2 <- signature(u_r = 'numeric', mu_r = 'numeric')
>fun.test <- cxxfunction(sig2, code2.0, plugin = "Rcpp")
>
>
>fun.test(1:4, 100)  
>sum(exp(1:4) > log(100))  # ok!
>##
>
>
>It works just fine. Now, I'd like to break it down into two functions like so:
>##
>code1 <-'
>  double x = as<double>(x_r),
>         y = as<double>(y_r),
>         ans;
>
>
>  ans = (exp(x)-y) > 0 ? 1 : 0;
>
>
>  return wrap(ans);
>'
>
>
>code2.1 <-'
>  NumericVector u   = as<NumericVector>(u_r);
>  double        mu  = as<double>(mu_r), 
>                v   = log(mu);
>  int           n   = u.size(),
>                res = 0;
>
>
>  for(int i=0; i<n; i++){
>    res += as<int>(fun1(u(i),v));
>  }
>
>
>  return wrap(res);
>'
>
>
>sig1 <- signature(x_r = 'numeric', y_r = 'numeric')
>sig2 <- signature(u_r = 'numeric', mu_r = 'numeric')
>fun.test <- cxxfunction(list(fun1 = sig1, fun2 = sig2), 
>                        list(code1, code2.1), plugin = "Rcpp")
>##
>
>
>But I get the error message:
># file5686a0c71e8.cpp: In function 'SEXPREC* fun2(SEXP, SEXP)':
>#   file5686a0c71e8.cpp:52:33: error: invalid cast from type 'double' to type 'SEXP'
># file5686a0c71e8.cpp:55:20: error: invalid cast from type 'Rcpp::traits::storage_type<14>::type {aka double}' to type 'SEXP'
>
>
>I then tried to change the types of 'u(i)' and 'v' to SEXP, but I get the same error:
>##
>code2.2 <-'
>  NumericVector u   = as<NumericVector>(u_r);
>  double        mu  = as<double>(mu_r), 
>                v   = log(mu);
>  int           n   = u.size(),
>                res = 0;
>  SEXP          us, vs = (SEXP) v;
>
>
>  for(int i=0; i<n; i++){
>    us = (SEXP) u(i);
>    res += as<int>(fun1(us,vs));
>  }
>
>
>  return wrap(res);
>'
>
>
>fun.test <- cxxfunction(list(fun1 = sig1, fun2 = sig2), 
>                        list(code1, code2.2), plugin = "Rcpp")
>##
># file5686a0c71e8.cpp: In function 'SEXPREC* fun2(SEXP, SEXP)':
>#   file5686a0c71e8.cpp:52:33: error: invalid cast from type 'double' to type 'SEXP'
># file5686a0c71e8.cpp:55:20: error: invalid cast from type 'Rcpp::traits::storage_type<14>::type {aka double}' to type 'SEXP'
>
>
>Is there any way to make it work?
>
>
>Thanks,
>Rubem
>
>
>
>
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